At the moment you can add anything that is on amazon.com (hopefully, let me know if you see any problems).

Accessory - 304
Antiques - 8
Apparel - 95
Art - 25
Audio Cassette - 1325
Audio Download - 2
Baby - 11
Bath Book - 6
Books - 60748
Calendar - 10
Cards - 18
CDs - 5796
Collectible - 193
Comic - 553
Craft - 98
Digital - 110
DVD - 2680
Electronics - 60
HD DVD - 60
Health and Beauty - 143
Imitation Leather - 3
Jewelry - 150
Kindle Edition - 1
Kitchen - 95
LP Record - 22
Magazine - 1406
Map - 11
Misc. - 225
Misc. Supplies - 19
MP3 CD - 23
Music Download - 1
Office Product - 61
Other - 316
Sheet music - 8
Single Issue Magazine - 3
Software - 290
Sports - 20
Stationery - 14
Theatrical Release - 15
Tools&Hardware - 23
Toy - 262
VHS Tape - 7313
VideoGames - 589
Vinyl - 51
Wireless Phone - 3
Wireless Phone Accessory - 8